Dear Moreno,
you can use the mean TR and add a covariate with the actual TR values
(or differences TR-meanTR) to take into account the different relaxation
times. This linear approximation holds if TRs are not too different.
Regards,
Michael.
Am 20.04.2011 17:47, schrieb moreno moreno:
> Dear SPM experts,
>
> I have got a problem about fMRI with the cardiac trigger.
> I mean that using the trigger, the TR becomes depending on the heart beats, and so if the heart starts to beat faster or slower , then there is a variable TR that is not constant in time.
> I would like to know if there is an option in SPM (version 8 or 5) that allowes me to use a variable TR. I don't know what to do. Thank you !
>
> Regards
>
> Moreno
>
>
>
--
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Dr. Michael Erb
Sektion f. experimentelle Kernspinresonanz des ZNS
Abteilung Neuroradiologie, Universitaetsklinikum
Hoppe-Seyler_Str. 3, D-72076 Tuebingen
Tel.: +49(0)7071/2987753 priv. +49(0)7071/61559
Fax.: +49(0)7071/294371
e-mail: <[log in to unmask]>
www: http://www.medizin.uni-tuebingen.de/nrad/sektion/
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
|